/*
 * MD5 hash in C
 *
 * Copyright (c) 2014 Project Nayuki
 * http://www.nayuki.io/page/fast-md5-hash-implementation-in-x86-assembly
 *
 * (MIT License)
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 * - The above copyright notice and this permission notice shall be included in
 *   all copies or substantial portions of the Software.
 * - The Software is provided "as is", without warranty of any kind, express or
 *   implied, including but not limited to the warranties of merchantability,
 *   fitness for a particular purpose and noninfringement. In no event shall the
 *   authors or copyright holders be liable for any claim, damages or other
 *   liability, whether in an action of contract, tort or otherwise, arising from,
 *   out of or in connection with the Software or the use or other dealings in the
 *   Software.
 */

static inline void md5_compress(ui32* state, const ui32* block) {
    #define ROUND0(a, b, c, d, k, s, t)  ROUND_TAIL(a, b, d ^ (b & (c ^ d)), k, s, t)
    #define ROUND1(a, b, c, d, k, s, t)  ROUND_TAIL(a, b, c ^ (d & (b ^ c)), k, s, t)
    #define ROUND2(a, b, c, d, k, s, t)  ROUND_TAIL(a, b, b ^ c ^ d        , k, s, t)
    #define ROUND3(a, b, c, d, k, s, t)  ROUND_TAIL(a, b, c ^ (b | ~d)     , k, s, t)
    #define ROUND_TAIL(a, b, expr, k, s, t)    \
        a += (expr) + UINT32_C(t) + block[k];  \
        a = b + (a << s | a >> (32 - s));

    uint32_t a = state[0];
    uint32_t b = state[1];
    uint32_t c = state[2];
    uint32_t d = state[3];

    ROUND0(a, b, c, d,  0,  7, 0xD76AA478)
    ROUND0(d, a, b, c,  1, 12, 0xE8C7B756)
    ROUND0(c, d, a, b,  2, 17, 0x242070DB)
    ROUND0(b, c, d, a,  3, 22, 0xC1BDCEEE)
    ROUND0(a, b, c, d,  4,  7, 0xF57C0FAF)
    ROUND0(d, a, b, c,  5, 12, 0x4787C62A)
    ROUND0(c, d, a, b,  6, 17, 0xA8304613)
    ROUND0(b, c, d, a,  7, 22, 0xFD469501)
    ROUND0(a, b, c, d,  8,  7, 0x698098D8)
    ROUND0(d, a, b, c,  9, 12, 0x8B44F7AF)
    ROUND0(c, d, a, b, 10, 17, 0xFFFF5BB1)
    ROUND0(b, c, d, a, 11, 22, 0x895CD7BE)
    ROUND0(a, b, c, d, 12,  7, 0x6B901122)
    ROUND0(d, a, b, c, 13, 12, 0xFD987193)
    ROUND0(c, d, a, b, 14, 17, 0xA679438E)
    ROUND0(b, c, d, a, 15, 22, 0x49B40821)
    ROUND1(a, b, c, d,  1,  5, 0xF61E2562)
    ROUND1(d, a, b, c,  6,  9, 0xC040B340)
    ROUND1(c, d, a, b, 11, 14, 0x265E5A51)
    ROUND1(b, c, d, a,  0, 20, 0xE9B6C7AA)
    ROUND1(a, b, c, d,  5,  5, 0xD62F105D)
    ROUND1(d, a, b, c, 10,  9, 0x02441453)
    ROUND1(c, d, a, b, 15, 14, 0xD8A1E681)
    ROUND1(b, c, d, a,  4, 20, 0xE7D3FBC8)
    ROUND1(a, b, c, d,  9,  5, 0x21E1CDE6)
    ROUND1(d, a, b, c, 14,  9, 0xC33707D6)
    ROUND1(c, d, a, b,  3, 14, 0xF4D50D87)
    ROUND1(b, c, d, a,  8, 20, 0x455A14ED)
    ROUND1(a, b, c, d, 13,  5, 0xA9E3E905)
    ROUND1(d, a, b, c,  2,  9, 0xFCEFA3F8)
    ROUND1(c, d, a, b,  7, 14, 0x676F02D9)
    ROUND1(b, c, d, a, 12, 20, 0x8D2A4C8A)
    ROUND2(a, b, c, d,  5,  4, 0xFFFA3942)
    ROUND2(d, a, b, c,  8, 11, 0x8771F681)
    ROUND2(c, d, a, b, 11, 16, 0x6D9D6122)
    ROUND2(b, c, d, a, 14, 23, 0xFDE5380C)
    ROUND2(a, b, c, d,  1,  4, 0xA4BEEA44)
    ROUND2(d, a, b, c,  4, 11, 0x4BDECFA9)
    ROUND2(c, d, a, b,  7, 16, 0xF6BB4B60)
    ROUND2(b, c, d, a, 10, 23, 0xBEBFBC70)
    ROUND2(a, b, c, d, 13,  4, 0x289B7EC6)
    ROUND2(d, a, b, c,  0, 11, 0xEAA127FA)
    ROUND2(c, d, a, b,  3, 16, 0xD4EF3085)
    ROUND2(b, c, d, a,  6, 23, 0x04881D05)
    ROUND2(a, b, c, d,  9,  4, 0xD9D4D039)
    ROUND2(d, a, b, c, 12, 11, 0xE6DB99E5)
    ROUND2(c, d, a, b, 15, 16, 0x1FA27CF8)
    ROUND2(b, c, d, a,  2, 23, 0xC4AC5665)
    ROUND3(a, b, c, d,  0,  6, 0xF4292244)
    ROUND3(d, a, b, c,  7, 10, 0x432AFF97)
    ROUND3(c, d, a, b, 14, 15, 0xAB9423A7)
    ROUND3(b, c, d, a,  5, 21, 0xFC93A039)
    ROUND3(a, b, c, d, 12,  6, 0x655B59C3)
    ROUND3(d, a, b, c,  3, 10, 0x8F0CCC92)
    ROUND3(c, d, a, b, 10, 15, 0xFFEFF47D)
    ROUND3(b, c, d, a,  1, 21, 0x85845DD1)
    ROUND3(a, b, c, d,  8,  6, 0x6FA87E4F)
    ROUND3(d, a, b, c, 15, 10, 0xFE2CE6E0)
    ROUND3(c, d, a, b,  6, 15, 0xA3014314)
    ROUND3(b, c, d, a, 13, 21, 0x4E0811A1)
    ROUND3(a, b, c, d,  4,  6, 0xF7537E82)
    ROUND3(d, a, b, c, 11, 10, 0xBD3AF235)
    ROUND3(c, d, a, b,  2, 15, 0x2AD7D2BB)
    ROUND3(b, c, d, a,  9, 21, 0xEB86D391)

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
}
